1. each element is made of extremely small particles (atoms)
2. All atoms in a given element are identical, but they differ from those of any other element
3. Atoms are neither created nor destroyed in any chemical reaction
4. A given compound always has the same relative numbers and kind of atoms

atoms combine to form

substances

atoms are made of particles that have an--

electric charge

ion

an atom that is electrically charged (+/-)

cation

an ion with a + charge

anion

an ion with a - charge

cobalt III

Co3+

cobalt II

Co2+

ions of different elements combine to form

ionic compound

chemical formula

tells us what kind of atoms/ions and how many/ratio

compounds are electronically

neutral

the formula of an ionic compound should be

reduced to give the smallest whole number ratio of ions

process by which a substance or substances are converted into different substances with new chemical and physical properties

Atoms that were -- replace other atoms that were --; atoms that were -- replace other atoms that were --!

For single and double replacement reactions, --cations, cations, anions, anions

when reactants react in a combustion rection, they always give off

CO2 and H20

atomic mass

the mass of a single atom (not in grams) given/measures in amu's (atomic mass unit)
atomic mass of any atom is based on the mass of a carbon atom
it's at the bottom of the square on periodic table

formula mass

sum of masses of all atoms in a compound

mole

the number of atoms of the element=the number of atoms in 12.0 g carbon-12

molar mass

the mass of a mole of a substance, or the mass of 6.02 x 10 up 23 particles of that substance

molar mass is the same thing as:

atomic mass

for a compound, molar mass is the same thing as:

formula mass

converting from mass-moles

molar mass (g/mol)

converting from volume to moles

22.4 Liters (only at STP)

converting from particles to moles

6.02 x 10 up 23

moles-moles conversion

ratio of moles in the equation

at a temperature of 0 degrees celcius, and a pressure of 1 atmosphere, 1 mole of any gas has a volume of

22.4 L...this is STP which stands for standard temperature and pressure

percent composition

the percent of the mass of compound made up by each element

empirical formula

formula that gives us the lowest whole number ratio of atoms in a covalent compound

molecular formula

formula giving actual numer of atoms in a covalent compound; not necessarily lowest terms
*in order to find molecular you have to find empirical

using chemical formulas and equations to figure out amounts of substances that undergo chemical changes

stoichiometry

matter is neither created nor destroyed, atoms cannot be gained or lost, even during a chemical reaction nothing is destroyed it just changes, the total mass of the reactants in a chemical reaction must equal the mass of the products.

law of conservation of matter

balanced chemical equations give us both the relative number of -- and the relative number of ---

--atoms/particles---moles

the reactant thats used up in a chemical reaction

limiting reagent

the reactant that's left over in a chemical reaction

excess reagent

the limiting reagent determines

how much product is formed!

in chemical reactions, atoms are rearaanged and new substances are formed. based on these arrangements, chemical reactions can either absorb or release--

energy

the energy exchanged between objects due to a difference in temperature

heat

study of changes in heat that accompany chemical reactions (chemistry having to do with heat)

thermochemistry

exothermic reaction

reaction that gives off or releases heat into the surroundings (-)

endothermic reaction

reaction that takes in or absorbs heat from the surroundings

measure of heat absorbed or released by a chemical reaction occurring at constant pressure

enthalpy change

enthalpy change for reactants in their standard state being converted to products in standard state.

standard enthalpy change

standard state (for enthalpy change)

1 atm and 25 degrees celcius

caloric theory

early scientists thought heat was an invisible, weightless liquid that flowed from hotter objects to cooler objects

kinetic theory

currently accepted; heat comes from the motion and vibrations of particles of matter.
heat is the transfer of kinetic energy (of motion) from a hotter object to a cooler one (at the atomic level so it's not visible)

an exothermic reaction releases heat, so the temperature of the surroundings

increase

an endothermic reaction absorbs heat, so the temperature of the surroundings

decreases

calorimetry

the study of heat flowand heat measurement, allows scientists to measure the standard enthalpy change by using calorimeter.

specific heat

the amount of heat required to raise 1gram of a substance by 1 degree celcius

describe a proton and its (charges, mass, and location)

charge of +1
mass of 1 amu
location- in the nucleus

describe an electron (charge, mass, location)

-1 charge
mass, so small we ignore
located outside nucleus

neutrons
describe location, charge, mass

no charge, neutral
mass about 1 amu
located inside nucleus

mass number

the sum of the protons and neutrons
found by taking the # protons and adding to the # neutrons

how do you know how many electrons there are?

there are the same number of electrons as neutrons, unless it has a charge in which case if it's positive there is one more electron and if it's negative that means there is one less

recall what you know about the electron

electrons only have specific energies
electrons have wavelike properties
we cant know the location and where the electron is going at the same time

What does the quantum mechanical model do?

describes the electron using the idea of ELECTRON DENSITY

region around the nucleus where there is a high probability of finding an electron of a given energy.

orbital

gives a definite electron path

orbit

lowest energy orbital to highest in letters; number of orbitals each one holds, and shapes

s, p, d, f
1 3 5 7
s=sphere
p=dumbbell
d, f =complex

if the quantum number/principal energy level is n=3, how many sublevels are there?

3

describe the characteristics of metals

location: left of zigzag
properties: shiny
good conductors of energy
solids at room temperature
malleable (can be hammered into a thin sheet)
ductile (can be pulled into thin wires)

properties of nonmetals

right of zigzag
not shiny
poor conductors of heat and electricity
may be solids, liquids, or gases
neither melleable, or ductile